Field of the Invention
This invention relates to an instrument for performing eye surgery, and more particularly to a method and instrument which takes advantage of bipolar cutting to remove the lens from the eye through a small incision while reducing the number of times that the instrument has to be passed through the incision.
From time to time the lens of the eye becomes opacified to the extent that vision is impossible. Opacified lenses are termed cataracts.
There is no presently known technology or treatment which will reverse the opacification of the lens. Accordingly, the preferred method of treatment for cataracts has been to surgically remove the lens and then to compensate for that removal by the substitution of an artificial lens.
The lens comprises a capsule which includes anterior and posterior portions. The capsule contains a nucleus surrounded by a cortex. The nucleus is comprised of relatively hard material while the cortex is a jelly-like material. There are currently several surgical methods for removing the lens. A common method is phacoemulsification. This procedure requires an incision into a portion of the eye called the limbus. A capsulotomy is then performed. This comprises an incision in the anterior capsule. A suitable ultrasound generating instrument of a type well known in the art is inserted through the incision into the capsule. The ultrasound emulsifies the nucleus into small pieces. The pieces of nucleus are then withdrawn from the eye and an artificial lens is substituted.
Many eye surgeons are uneasy about using this procedure since there is risk that the ultrasound will tear the posterior capsule and that fragments of the nucleus of the lens will be lost in the vitreous of the eye.
It is also known to remove the lens by phacofragmentation. In this procedure the surgeon inserts an anvil behind the nucleus and then cuts through the nucleus against the anvil with a knife. The cut sections of the nucleus are then withdrawn through the incision. The anvil is used because cutting completely through the nucleus entails the risk that the posterior capsule will be cut and the nuclear fragments will go into the vitreous of the eye from which they are difficult to remove.
It would be advantageous to have an instrument which would avoid the problems associated with phacoemulsification and be able to cut the anterior capsule and remove the nucleus without the need for a second instrument and without the need for the instruments to be inserted and removed from the eye several times during the surgery.
With the foregoing in mind the invention relates generally to an instrument for surgically removing the lens from the eye comprising means for cutting a groove in the lens and splitting the lens at the groove, and means for removing the pieces of lens.
In another aspect, the invention relates to a method for removing the lens from the eye comprising the steps of removing the anterior capsule, cutting a groove in the nucleus of the lens with a bipolar cutter, separating the lens into at least two pieces and removing the pieces.